Rattling noise, kind've sounding like a cowbell like noise

What is your question?

I had just dropped off my son leaving my car on during the time, I went 4 or 5 blocks and then noticed a noise starting that sounding like a cowbell noise, so I pulled over and opened up the hood and noticed a wire moving around and hitting a few belts. It honestly sounds like something came loose or broke loose. But I am not for sure.